Circuit interrupter



(X50 77/ I ka r/ Randa/l Jan. 12, 1943. K. c. RANDALL 2,308,303

CIRCUIT INTERRUPTER I -Filed June 28; 1940' '2 Sheets-Sheet ,1

w|TNEssEs i vENToR Jan. 12, 1943. S 'K. c. RANDALL ,3 3

I CIRCUIT INTERRUPTBR Filed June 28, 1940 2 Sheets-Sheet -2 I WITNESSES:

INVENTOR O 2 WW I Ker/'6. Randa/l Patente d Jan. 12, 1943 Tic CIRCUIT INTERRUPTER Karl C. Randall, Edgewood, Pa., a'ssignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 28, 1940, Serial No. 342,924

19 Claims.

My invention relates generally to electric circuit interrupting devices, and more particularly to such devices embodying separable contacts, such as disconnecting switches.

It has been found that instead of attempting to obtain perfectly flat contact surfaces of substantial area in devices of this type, that at least as good, and in most cases better electrical contact may be obtained when using'the same total pressures, by limiting the contact area and thereby raising the pressure per unit of contact area and providing more intimate engagement of the contacting surfaces. This principle is well recognized and has been embodied in conventional switch apparatus as shown, for example, in the patent to Herbert J. Crabbs, No. 2,208,411, issued July 16, 1940, and assigned to the assignee of this application. Such switch structures, however, have considerable contact friction at least for a portion of the movement of the switch. If contact portions of a noble metal having high conductivity are used, the rubbing of the contact portions under relatively high pressure is undesirable particularly when a relatively soft metal, such as silver, is used.

Accordingly, one object of my invention is to provide a novel circuit interrupter including high pressure, limited area separable contact portions, wherein substantially no sliding friction of the contacting portions occurs.

Another object of my invention is to provide a circuit interrupting device with novel limited area, high pressure, substantially self-freeing separable contact portions.

Another object of my invention is to provide a circuit interrupting device with novel pressure, separable contact means.

Another object of my invention is to provide a circuit interrupter having independently mounted separable contacts, which contacts embody self-aligning interengaging contact portions.

Another object of my invention is to provide a circuit interrupter embodying separable contacts, with novel operating means for causing high pressure engagement of said contacts.

Th se and other objects of my invention will become more apparent upon consideration of the following detailed description of preferred embodiments thereof, when taken in connection with the accompanying drawings, in which:

Figure l is a side view of a disconnecting switch embodying my invention with the. switch shown in its fully closed position, and with portions of the insulator supports broken away;

Fig. 2 is a side view of the disconnecting switch shown in Fig. 1 with the switch illustrated in a partially closed position;

Fig. 3 is a top view of the disconnecting switch shown in Figs. 1 and 2 with the switch in the closed position shown in Fig. l; r

Fig. 4 is 'a side elevational view of a disconnecting switch illustrating another form of my invention with the switch in a fully closed position, and with portions of the insulator supports broken away; and

Fig. 5 is a fragmentary longitudinal sectional view illustrating a contact construction, some of the features of which may be used in connection with the disconnecting switches shown in Figs. 1 to 4.

Referring to Figs. 1 to 3 of the drawings, I have shown a switch which includes a pair of spaced supporting insulators 2 and i. The insulators 2 and 4 may be of conventional design and are preferably made of porcelain, glass, or any other desired insulating material. As shown in Fig. 2, the insulators 2 and 4 may be secured to a supporting plate 6 as, for example, by the bolts 8. The insulator 4 supports a hinge contact construction which includes a contact support 10, secured to the insulator cap 9 as, for example, by the bolts l8. At the end of the contact support Ill adjacent the insulator 2, I provide a contact supporting flange l2 integral with the support Ill, andspaced therefrom, I provide a second contact supporting flange l l' also integral with the base Ill. The base 10 and supporting flanges l2 and It may be made of any desired conducting material such, for example, as copper or a copper alloy. The supporting flange 12, as shown, is relatively thin in order to provide for some flexibility and resiliency thereof. The con tactsupport It! further includes an integral extension l i which extends outwardly of the insulator 4 to provide a terminal portion for connection of a line conductor thereto. The supporting flange I 4 is provided with integral outwardly extending spaced pivot supporting arms 20 for pivotally supporting the switch blade 42 as will be hereinafter further described. The contact supporting flanges l2 and 15 have fixedly secured thereto opposite ends of a contact base member 22 which may be made of any desired conducting flexible and resilient material such, for example, as a copper alloy. The contact base 22 is in the form of an elongated strip, as shown in Fig. 3, having its opposite ends secured to the upper end of the supporting flange l2, and to the supporting flange 14 between the pivot sup- The other insulator 2 likewise has securedto the cap 21 thereof, as by bolts 26, a contact sup-.

porting base member 28. The contact support 28 is provided with an integral supporting flange 30 at one end thereof, and a second integral sup.- porting flange 32 spaced from the flange 38. The support 28 further includes a terminal extension 34 similar to the extension It on the contact support Id. The supporting flange 32 is provided with spaced locking extensions 38 adapted to cooperate with the switch operating means to lock the same in a closed position. The supporting flanges 30 and 32 support a contact base strip 38 of a flexible and resilient conducting material like the contact base 22. However, the contact base 38 is secured solely to the supporting flange 32 between the locking extensions 38 in a fixed manner, such, for example, as by welding or the like, and the other end of the contact base 38 is adapted to rest freely on the upper edge of the supporting flange 38. The contact base 38,

the cross section of the pivot pin 45 to allow for limited movement in a plane laterally of the in- 'sulators 2 and 4 for a purpose to be hereinafter described. The blade 42 is provided with laterally extending contact projections 48 and 50 adjacent opposite ends thereof, the contact projections ,5 0

48 and 58, like the projections 24 and 48, are also provided with convex opposed side walls. An operating handle 52 is pivotally mounted at the free end of the blade 42 as by the pivot pin 55.

As is moreapparent from Fig. 3, the operating handle 52 may comprise a pair of strap members, welded, or otherwise secured together for the major portion of their length, with adjacent end portions thereof offset, as at 54, to be positioned at opposite sides of the switch blade 42 for pivotal connection with the outer ends of the pivot pin 58. The locking extensions 36 on the supporting flange 32 are provided with laterally extending cam arms 58, having lower cam surfaces 68 terminating in a locking indentation 62 ad,

jacent the locking extensions 38. The cam surfaces 88 are formed to gradually approach the contact projections 48 towards the inner ends thereof, and their outer ends are formed with sharply upwardly curved portions 8|. surfaces 58 are adapted to cooperate with a cam follower in the form of a roller 64 mounted on the operating handle 52. As shown, the operating handle 52 has the outer end thereof formed The cam with an annular portion 66 to form a hook-eve cam surface 68 on the cam arms 58.

for the reception of a hookstick operating member, or the like.

In the operation of the disconnecting switch shown in Figs. 1 to 3, the structure of which has been described above, assuming the switch to be in a fully opened position, in order to close the switch it is first moved to substantially the position shown in Fig. 2. When the switch is fully opened and the contact projections 48 and 50 on the blade 42 are entirely out of engagement with respect to the contact projections 24 and 40, the contact supporting bases 22 and 38, due to their inherent resiliency, will normally assume a substantially straightened position, such as the position shown in Fig. 2 for the contact base 38. As the switch blade is moved by the operating handle 52 towards the closed position, the contact projection 48 will first engage between the contact projections 24 on the insulator 4. In this form of my invention, I prefer to make the contact projections 48 and 50 on the blade 42 of a size to freely fit between the projections 24 and .48,-respectively, when the contact bases 22 and 38 are in a straightened condition. Therefore, when the switch is moved towards its closed position, the contact projection 48 on the switch blade will first substantially freely enter between the projections 24 on the contact base 22 to engage the portion of the base 22 between the projections 24, and upon continued movement of the blade 42 in a counterclockwise direction, as seen in Figs. 1 and 2, the contact base 22 and supporting flange l2 may be flexed to the position shown in Fig. 2. The contact projections 48 and 24 engage prior to engagement of the projections 48 and 58 because the end of the blade adjacent the pivot 46 necessarily moves a smaller distance than does the outer end of the blade carrying the projection 50. The primary engagement of contact projections 24 and 48 is not objectionable, however, in View of the extremely long lever arm between the operating handle pivot 58 and blade pivot 46, as compared to the small lever arm between the pivot 48 and con tact projection 48. Therefore, even though the material of the contact base 22 is relatively stifl",

flexure of this member to the position shown i Fig. 2 is relatively easily accomplished.

The next thing which occurs in the closing movement of the switch blade 42 is engagement of the blade contact projection 58 between the projections 40 on the contact base 38. This is the position shown in Fig. 2 of the drawings, and

continued movement of the operating handle 52 in a counterclockwise direction from the position shown in Fig. 2 results in relative pivotal movement of the operating handle with respect to the blade 42 about pivot 56, with the cam roller 64 on the handle in engagement with the This movement results in the application of pressure to the outer end of the switch blade 42, causing a slight further downward movement of the projection 48, and considerable downward movement of the projection 58 on the switch blade to the position shown in Fig. 1, when the cam roller 84 is seated in the locking indentation 82, to effectively lock the switch blade in this position. The considerable downward movement of the outer end of the blade 42 causes the contact projection 59 to flex the contact base 38 in a substantially arcuate manner, as clearly shown in Fig. 1.

I desire to again particularly point out that the contact projections 48 and 58 are of a size in relation to the spacing of the contact. projections 24 and 69, so that when the contact bases 22 and 33 are in a straightened condition, the projections cc and 50 may freely enter be tween the contacts 24 and d0, respectively; In the straightened condition of the contact bases 22 and 38, the contact projections 24 and Mlare designed to extend substantially laterally or perpendicularly with respect to the contact bases 22 and 38. Now when the bases are flexed to the positions shown in Fig. l in an arcuate manner, obviously the projections 2 and 40 being integral with the bases 22 and 38, respectively, will maintain their normal relation with respect to the bases and hence will extend substantially radially with respect to the curvature of the bases, and therefore will have their outer ends moved inwardly towards each other. This will press outer portions of the contact projections 24 and iii into engagement with the outer sides of the blade projections 48 and 50, respectively. Obviously, the pressure of this engagement can easily be made quite high because of the advantageous high ratio of the distance between the center of each contact base and its end supports, as compared to the height of a contact projection supported thereon. I also desire to point out that this high pressure engagement of the contact projection will be substantially along a line extending longitudinally of the projections, or laterally with respect to the blade and contact supports 22 and 38, inasmuch as the contacting surfaces of the projections are outwardly convex.

It should be noted that in the closing movement of the switch, any disalignment of projection is with respect to projections 24 due to manufacturing or assembling inaccuracies will be compensated for by the loose pivotal connection td, d6 of the switch blade, to permit the projection ts on the blade to locate itself between the contact projections 24. Also, any disalignment of the blade contact projection 59 with respect to the contact projections 40 will be compensated for by the particular mounting of the contact base 38. As shown, the contact projections All and 58 have outer convex surfaces so that when brought into engagement, any slight disalignment will tend to provide the projection as with a camming sheet on one or the other of projections M9, to flex the contact base 38 which is capable of considerable movement in view of the free method of supporting one end thereof on the supporting flange 3B.

When it is desired to move the switch from the position shown in Fig. l to an open position, it is merely necessary to move the operating handle 52 in a clockwise direction as viewed in Fig. l, and after movement of the cam roller 64 on the operating handle 52 from the locking indentation 62 on the cam arms 58, the contact projections are adapted to free themselvesfrom th high pressure engagement shown in Fig. 1, due to the resiliency of the contact bases 22 and 38 which, having been stressed to the positions shown in Fig. 1, will automatically restore themselves to straightened positions such, for example, as the straightened position of the base 38 shown in Fig. 2. This not only operates to move the switch blade 42 in a clockwise direction upwardly from the position shown in Fig. l,

but also operates to separate the contact projections 24 and 40 to thereby free the blade projections 48'and 50 so that the entire opening movement of the blade is substantially frictiontions thereof.

less,: at least being unopposed by any contact friction. This is an important feature "of my invention. especially if a noble metal such as silver; or the like, is used on the contacting surfaces of the contact projections, inasmuch as such materials have certaindisadvantages when in high pressure frictional engagement. It should also be noted that the contacting pressures obtained between the contact projections in the closed position of the switch may be predetermined by the resilient properties of the con-' tact. supports 22 and 38, respectively, and may be made at any desired value up to a high value determined .by the strength of the materials employed.

Referring to Fig. 4, I have shown another form of disconnecting switch embodying certain principles of my invention, and inasmuch as certain parts of this switch are the same as corresponding parts of the switch shown in Figs. 1 to 3 of the drawings, like reference numerals will be used to designate such parts. As shown in Fig. 4, the insulator 4 in this embodiment of my invention has secured to its end cap 9, a contact supporting plate Hi having a terminal extension '32 for the connection thereto of the line conductor. The supporting plate ill is provided with a central, integral, elongated projecting contact base M, for supporting a pair of contact spaced projections 16. The contact projections 15 have opposed contacting side walls, with'the curvature of the inner facing walls of the projections being arranged so that a slot is formed between the projections with the walls of the slot arcuately flaring outwardly.

The insulator 2 similarly, has seemed to its end cap 21 a contact base 18 provided with a terminal extension 86. The contact base 18 is provided with spaced opposed supporting flanges 82 and 86, each of which is provided with facing arcuate supporting surfaces 34 and 8%, respectively, which surfaces are in the form of reverse curves curves with the lower portions of such surfaces being closer together than the upper por- The supporting flange 8'5 is provided with a central pivot supporting flange 99 integral therewith, and extending toward the supporting flange 82 for pivotally supporting the contact base member 96. The contact base member 96 is provided with a slot for receiving the flange 95!, and a pivot pin E2 is adapted to be passed through the contact base 96 and through an enlarged aperture in the pivot supporting flange for loosely pivotally connecting the con tact base 96 with the supported flange 53. As shown, the contact base is provided with curved ends 91 adapted to be seated on the outer portions of the curved supporting walls 8d and G8, respectively, of the supporting flanges 82 and 8'5.

The sole connection of the contact base 5 with the contact support 18 and its supporting flanges is by means of the pivot pin 92 fitting loosely in the pivot aperture 94. A coiled compression spring 98 is provided between the contact base 96 and the contact support 18, with the ends thereof seated in suitable recesses in these parts to locate the same. In the position shown in Fig. 4 the coil spring 98 is compressed so that when the switch is open the contactjbase 55 will be moved by the spring 98 to the dotted line position shown in Fig. 4, into engagement with the stop lug lllfl formed on the spaced locking extensions [04 integral with the supporting flange 82. The contact base 96 is also provided with a pair of spaced contact projections Hi2 similar in construction to the projections I6, previouslyde scribed. I

The switch blade I in this'embodiment of my invention is movably connected to the contact base I4 by means of a pair of pivot links I08 (only one of which is shown) having opposite ends thereof pivotally connected to the blade I 06 and contact base I4, by pivot pins II2 and H0, respectively. The pivot pin IIO connecting the links I03 to the contact base I4 is receivedin'a slot I 09 formed in an extension of the base", and is normally maintained in the lower end of the slot I09 by a coil compression spring III located between the pivot pin H0 and one end of slot I00, for a purpose to be hereinafter referred to. The blade I 05 is provided with contact projections II 4 and H6 adapted to engage between the contact projections I6 and I 02, respectively, in the closed position of the switch. The blade is further provided with an operating handle 52, like that described in Figs. 1 to 3 of the drawings, and which is adapted to lock the switch blade in its closed position in the same manner previously described, and, therefore, the structure and function of these parts will not be repeated.

In the operation of the switch disclosed in Fig. 4, assuming the switch to be in the fully open position, the contact support 96 will then be in a position corresponding to the dotted line position shown in Fig. 4 in engagement with the stop lug I00. Now upon movement of the switch blade in a counterclockwise direction to close the switch the link connection I08 of the blade to the contact base I4 permits movement of the blade laterally relative to the contact projections I6 to enable the projection I I4 to be self-aligning with respect to the contact projections I6, and engagement of blade contact projection II6 with the contact projections I02 by virtue of the resiliently biased relatively loose pivotal support of the contact base 96 will enable the blade contact projection II6 to move the projections I02 and consequently the contact base 96 to an aligned position, to thereby account for any possible disalignments due to manufacturing or assembling inaccuracies in these switch parts. As the switch is moved to its fully closed position and pressure is applied to the blade by cooperation of the cam roller 04 with the cam surface 60, the blade contact projections II4 and H6 come into relatively high pressure engagement with the contact projections I6 and I02, respectively. In this embodi ment of my invention, in closing the switch the contact projections H6 and I02 will engage first to automatically align these parts, and move the gages the fixed contact projections I6. Further movement in the closing direction of the blade I05 results in high pressure engagement of the contact projections and also acts to force the contact base 96 into intimate conductive engagement with the supporting surfaces 84 and 88 on the supporting flanges 82 and 85, respectively, and also compresses the coiled compression spring 98. Any vertical disalignment of the insulators 2 and 4, and consequently of the contacts I6 and I02, is taken care of by the resilient support for pivot pin I I0 of the switch blade I06. In other words, if the contact projections I6 are in a plane above the contact projections I02, these contacts will be engaged first, and the blade will pivot about its contact projection II 4 to engage its contact projection II6 with the projections I02. This pivotal movement about the plate contact projection- II 4 is permitted by movement of the pivot pin IIO upwardly in slot I09 against the force exerted by the spring I I I. The contact supporting parts I0 and 14 are preferably of a size to support contact projections 10 slightly outwardly of the plane of contact projections I02 so as to insure high pressure engagement of contact pro jections I02 and 6.

Opening movement of the switch in this embodiment of my invention is also resiliently aided by the spring 98. The coiled compression spring 98 when the switch blade is opened, also aids in freeing the contact projections I6 and H4 from the blade contact projections, and furthermore, because of relative tilting movement between the switch contact base 96 and the switch blade I06 and hence between the contact projections I02 and H6 during switch opening movement, also has the function of freeing these contact projections, so that it is apparent I have also provided in this embodiment of my invention, substantially self-freeing contacts.

It should be noted that the contact projections H4 and II 6 on the switch blade in this embodiment of my invention are made to be substantially wider than the bottom portion of the slot formed between the contact projections I6 and, I02, respectively. Therefore, the projections H4 and H6 are not permitted to penetrate the full depth of the slot between the contact projections I6 and I02, so that the convex side walls of these projections engage with substanitally line contact portions at points spaced above the contact bases 96 and I4. This contact construction provides for substantially a wedging action upon engagement of the switch contact portions.

In Fig. 5 of the drawings, I have illustrated a contact construction including a contact base I I8 which may be supported in the same manner as the contact bases 22 and 38 shown in Figs. 1 to 3 of the drawings. I have also shown interengaging contact projections I28 and I20 which are capable of use either with the switch in Figs. 1 to 3 of the drawings or with the switch shown in Fig. 5. The contact base H8 in this embodiment of my invention, however, may have little, if any, resiliency and is preferably relatively thin and flexible, and may be of any suitable flexible conducting material, such for example, as a relatively thin copper strap. Inasmuch as the base II8 has little or no resiliency, a coiled compression spring I24 is provided between the contact support I22 and the base II8 for returning the base to substantially a straightened position when the switch is open. When the switch is closed, of course, the base may be arcuately flexed in the manner shown in Fig. 5 to bring the contact projections I20 integral with the base into high pressure engagement laterally with the contact projection I 28 formed on the switch blade I26. The configuration of the contact projections in this embodiment of my invention is similar to that of the projections described in connection with the embodiment shown in Fig. 4. However, Fig. 5 being on an enlarged scale, the line contact of the projection is more readily apparent at the corners I30 of the blade contact projection I28. As shown in Fig. 5, the contact projections I20 and I20 are provided with a coating I32 of low resistance material such, for example, as a noble metal, such as silver or the like, to provide contacting surfaces which will be substantially non-corrosive and resistant to deterioration. Obviously, if desired, this coating or layer may be confined solely to the contacting surfaces of the contact projections rather than being on all exposed surfaces of these projections.

The operation of the contacts in opening and closing an interrupter in accordance with the construction shown in Fig. is very similar to the operation of the switches previously described and, therefore, this operation will not be recited in detail. It is thought sufficient to state that limited area high pressure contact is obtained without employing any contact friction. It is believed obvious that this contact construction will be self-freeing in the same manner as the contact construction shown in Figs. 1 to 3 of the drawings. This construction has the advantags that none of the current carrying parts is required to be of a resilient material, inasmuch as the spring I24 may be of a high resistant material and does not necessarily carry current.

From the foregoing, it is believed to be apparent that I have particularly disclosed certain forms of disconnecting switches, constructed in accordance with my invention, which fea ture in general, limited area, high pressure, selfaligning separable contacting portions, without resorting to any sliding friction on the contacts, and wherein the contacts on all forms of switches disclosed are self-freeing from their high pressure engagement. It should also be noted that I have provided in circuit interrupters embodying interfitting separable contacts, means to compensate for any disalignment of the interfitting parts which might be occasioned by manufacturing or assembling inaccuracies so that careful and extensive machining of such parts is not required, rendering it possible to economically construct a switch of this type. The switches disclosed are also provided with a novel construc tion and arrangement of parts for obtaining high pressure engagement of separable switch contacts and these, as well as numerous other novel features disclosed, are all intended to be comprehended as parts of my invention.

Having described preferred embodiments of my invention in accordance with the patent statutes, I desire it to be understood that my invention is not limited to the particular structures disclosed herein, inasmuch as it will be obvious, particularly to persons skilled in the art, that many changes and modifications may be made in these structures without departing from the broad spirit and scope of my invention. Therefore, I desire that my invention be interpreted as broadly as possible and that it be limited only by what is expressly stated in the following claims.

I claim as my invention:

1. In a circuit interrupter including separable contact means, the combination wherein one of said contact means includes a flexible supporting member supported at spaced points and having spaced relatively rigid contact projections fixed thereto intermediate said supporting points, and the other of said contact means includes a cooperating contact projection adapted to be received between said first mentioned projections to flex said supporting member and provide high pressure lateral engagement of said projections.

2. In a circuit interrupter including separable contact means, the combination wherein one of said contact means includes a flexible and resilient supporting member supported at spaced points and having spaced relatively rigid contact projections fixed thereto intermediate said supporting points, and the other of said contact means includes a cooperating contact projection adapted to be received between said first mentioned projections to flex said supporting member and provide; high pressure lateral engagement of said projections.

,3. In a circuit interrupter including separable contact means, the combination wherein one of said contact means includes a flexible supporting member supported at spaced points and havhaving spaced relatively rigid contact projections fixed thereto intermediate said supporting points, and the other of said contact means includes acooperating contact projection adapted to be received between said first mentioned projections to flex said supporting member and provide high pressure lateral engagement of said projections,and biasing means opposing said flexing movement of said supporting member.

4. In a circuit interrupter, a contact member including a projecting contact portion mounted for movement into and out of engagement with respect to a cooperating contact, said cooperating contact including spaced relatively rigid contact portions adapted to receive said projecting contact portion therebetween and a flexible supporting base member fixedly supported at spaced points and carrying said spaced contact portions intermediate said supporting points, said supporting base member normally assuming an unflexed position when said interrupter is open, so as to be flexed by said contact member in the closed position of said interrupter to cause said spaced contact portions to laterally engage said projecting contact portion under pressure.

5. In a circuit interrupter, a contact member including a projecting contact portion mounted for movementin a fixed path into and out of engagement with respect to a cooperating contact, said cooperating contact including a relatively rigid projecting contact part positioned to be closely adjacent one side of said contact projection in the closed position of said interrupter, and a flexible supporting member supported at spaced points and rigidly carrying said contact part intermediate said supporting points so that said contact part is moved laterally into engagement'with said contact projection upon pressure engagement of said contact member and supporting member at a point intermediate said spaced points.

6.. In a circuit interrupter, a contact member including a projecting contact portion mounted for movement into and out of engagement with respect to. a cooperating contact, said cooperating contact including spaced relatively rigid projecting contact portions adapted to receive said projecting contact. portion therebetween and a flexible supporting base member supported at spaced points and fixedly carrying said spaced contact portions intermediate said supporting points, said. supporting base normally assuming an unflexed position when said interrupter is open, so as to be flexed by said contact member in. the closed position of said interrupter to cause said spaced contact portions to laterally engage said projecting contact portion under pressure, and said supporting. base being resiliently biased to said normal position whereby to freely release said. projecting contact portion upon movement thereof out of engagement with respect to said cooperating contact- '7. In a circuit interrupter, a. contact member including a projecting contact portion mounted for movement in a fixed path into and out of engagement with respect to a cooperating contact, said cooperating contact including a relatively rigid contact part positioned to be closely adjacent one side of said contact projection in the closed position of said interrupter, and said cooperating contact means further including a flexible support member rigidly carrying said contact part and which is supported at a point spaced on the opposite side of said contact part from the point of engagement of said contact portion whereby, upon pressure engagement of said contact member and contact means, at least a portion of said contact part is moved laterally into pressure engagement with said contact projection.

8. A contact member including a flexible base member adapted to be supported at spaced points, and relatively rigid, spaced projecting contact portions integral with a portion thereof intermediate said spaced points.

' 9. A contact member, including a flexible base member, intermediate, spaced, laterally extended opposed contact portions rigid with said base member, spaced supporting means for said base member, at least one of which is fixedly secured to said base member to permit flexure thereof.

10. A contact member including a flexible base member, intermediate, spaced, laterally extending contact portions rigid with said base member, spaced supporting means for said base member one of which is fixedly secured to said base member, and the other of which movably supports a spaced part of said base member to permit fiexure thereof.

11. A contact member, including a flexible base member, intermediate, spaced, laterally extending opposed contact portions rigid with said base member, spaced supporting means for said base member at least one of which is of flexible material, and both of said supporting means being fixedly secured to said base member to permit fiexure thereof.

12. In a circuit interrupter, separable contact means at least one of which is mounted for movement into and out of engagement with respect to the other of said contact means, said contact means including base members with interfitting substantially tongue and groove contacting portions fixed on said base members, respectively, and with the groove extending at an angle to the plane of movement .of said one contact and adapted to provide limited area high pressure contact in the closed position of said interrupter, and one of said base members being mounted for movement substantially laterally of said first movement to compensate for any disalignment of said contacting portions.

13. In a circuit interrupter, separable contact means at least one of which is mounted for movement into and out of engagement with respect to the other of said contact means, said contact means including base members with interfitting substantially tongue and groove contacting portions extending at an angle to the plane of movement of said one contact and adapted to provide limited area high pressure contact in the closed position of said interrupter, and said one of said base members being mounted for movement substantially laterally of said first movement to compensate for any disalignment of said contacting portions.

14. In a circuit interrupter, spaced contacts,

and a bridging contact mounted for movement 75 into and out of engagement with respect to said spaced contacts, said contacts including interfitting substantially tongue and groove contacting portions with the groove extending at an angle to the plane of movement of said one contact and adapted to provide limited area high pressure contact in the closed position of said interrupter, said bridging contact being also mounted for lateral movement with respect to said spaced contacts to accommodate any disalignment in at least one of said spaced contacts,

and one of said spaced contacts being movable toward and away from the other of said spaced contacts to compensate for non-uniform spacing of said contacting portions.

15. In a circuit interrupter, separable contact means at least one of which is mounted for movement into and out of engagement with respect to the other of said contact means, said contact means including limited area contacting portions, operating means movably associated with said movable contact means, and relatively fixed pressure applying means positioned to cooperate with said operating means adjacent the closed position of said interrupter to apply pressure to said contacting portions by relative movement of said operating means with respect to said movable contact means.

16. In a circuit interrupter, separable contact means at least one of which is mounted for movement into and out of engagement with respect to the other of said contact means, said contact means including limited area contacting portions, operating means movably associated with said movable contact means, pressure applying means positioned to cooperate with said operating means adjacent the closed position of said interrupter to apply pressure to said contacting portions by relative movement of said operating means with respect to said movable contact means, and means for locking said interrupter in a closed position with said contacting portions in high pressure engagement.

1?. A contact member including a flexible base member adapted to be supported at spaced points, and spaced, rigid projecting contact portions fixed to portions of said base member intermediate said spaced points.

18. In a self-aligning contact structure, a floating contact member loosely pivotally mounted adjacent one end thereof for pivotal movement about said one end and for limited movement laterally of said pivot axis, and means for biasing said contact member for movement in a di-# rectio e a y towards a cooperating contact member.

19. In a circuit interrupter including separable contact means, the combination wherein one of said contact means includes a flexible supporting member having spaced, rigid contact projections fixed thereto, the other of said contact means including a cooperating contact projection adapted to be received between said first mentioned projections, actuating means movably mounted on said other contact means for moving said contact projection of said other contact means into and out of a position between said spaced contact projections, and force-multiplying means operative in response to relative movement of said actuating means when said cooperating contact projection is in said position between said spaced contact projections to flex said supporting portion and provide high pressure lateral engagement of said projections.

- i '1' KARL C. RANDALL. 

